Multicylinder reciprocating piston machine



4 sheetssheet 1 C. .SCHA

Filed March 24, 1934 MULTICYLINER RECIPROCTING PISTON MACHINE 4 Sheets-Sheet 2 c. SCHAER MULTICYLINDERRECIPROCATING PISTON MACHINE Filed March 24, 1934 Oct. 6, 1936.

Oct. 6,1936. c. SCHAER @559622 MULTICYLINDER RECIPROCATING PIsToN MACHINE Filed March 24, 41934 4 Sheets-Sheet 5 AT1-12| RN D@ 07W AWM* @ma C. SCHAER oct, 6, v193.,

MULT I CYL INDER` REC I PROCATI NG PISTON- MACH INE Filed waren 24, 1934 4 Sheets-Sheet 4 KNK-f ATI-u RN a/s Patented Oct. l 6, 1936 PATENT OFFICE MULTICYLINDER RECIPROCATING 'v PISTON MACHINE Charles Schaer, Winterthur, Switzerland, as-

signor to the firm of Sulzer Frres Societe Anonyme, Winterthur, Switzerland Application March 24, 1934, Serial No. '717,198 In Switzerland'Aprl 4, 1 933 12 claims. (ci. 12s-'195) This invention relates to multi-cylinderreciproeating machines such, for example, as internal combustion engines, steam engines or reciprocating compressors. More particularly, the invention relates to reciprocating piston apparatus of this sort which is constructed with composite or welded frame structures, and the invention aims to provide an improved Welded frame structure for such apparatus.

In reciprocating multi-cylinder engines the rigidity of the engine frame as usually constructed is dependent upon the rigidity of the crank case, the cylinders, from which the forces due to pressure of the working medium are transmit- 'ted to the frame, being mounted on the crank case either individually or in blocks. In such constructions, therefore, the rigidity of the structure as a Whole is dependent on an element to which the forces are only indirectly transmitted from the cylinders.

In the case of welded frames if rigidity is dependent on all parts of the frame collectively, accessibility to the working parts within the frame is liable to be impaired; whilst, if the frame is dependent for its rigidity upon the individual cylinders or groups of cylinders and the crank case, undesirable forces are apt to be transmitted from one cylinder to another and thus indirectly to the frame and crankshaft bearings.

The primary object of the invention is to provide a welded frame reciprocating piston appa- .ratus having a remarkably high degree of rigidity for the amount of material used.

Another object of the invention is to provide a welded frame reciprocating piston apparatus in which the working parts are made readily accessible Without impairing the rigidity of the structure.

Another object of the invention is to simplify the outline of the engine and reduce the number of parts having complicated structural shapes which tend to increase the cost of manufacture.

A further object of the invention is to provide a convenient mounting for those parts which control the operation of the engine, such, for example, as the cam shaft, and valve actuating mechanism.

A still further object of the invention is to provide a welded frame construction in which the cooling medium for the cylinders isy prevented for coming in contact with the welded joints of the frame, thereby preventing the deterioration ofthese joints by corrosion- To these ends a multi-cylinder reciprocating nissan machine according to the present invention comprises a box-girder-like member of weldable metal having openings to receive the cylinders, to which frame member the cylinder heads may be bolted, and to which metal plates can be welded -to constitute a supporting frame between the box-girder-like member and the crankshaft bearings, the box-girder-like member thus constituting a stiiening for the supporting frame so that both transverse and longitudinal forces are taken up by the box-girder-like member.

In this way that part of the engine frame from which the driving forces originate, i. e., the cylinders, constitutes the stiffening for the frame so that undesirable deection of the intermediate members between the cylinders and the frame is avoided.

The invention will be further understood from a consideration of the accompanying drawings wherein, by Way of example, a number of embodiments of the invention are illustrated.

In these drawings:

Figure 1 is a side elevation on the line Fig. 2,

Figure 2 is a section on the line II-II of Figure l,

Figure 3 is a plan view part being shown in section on the line III-III of Figure 2 and part in section on the line IV-IV of Figure 2,

Figure 4 illustrates in a manner similar to that of Figure 2 another construction also according to the invention,

Figure 5 is a transverse section taken on line 6--6 of Fig. 4,

Figures 6 and 7 illustrate in longitudinal and transverse section respectively a further construction also according to the invention,

Figure 8 is a transverse section through one cylinder head of a construction which is a modi-I cation of that shown in Figures 6 and 7.

Figures 9 and 10 show respectively in longitudinal and transverse section yet another construction also according tothe invention, and

Figure 11 is a vertical transverse section through the upper portion of an internal combustion engine illustratingthe use of a modified form of boxgirder-like` member.

Referring first to Figs. 1 to 3 voi the accompanying drawings, the engine frame includes a boxgirder-like substantially rigid unitary structural member 3 made, for example, of cast steel. The shape of this member may be understood from Figs. 2 and 3 from which it will be seen that boxgirder-llke member 3 is comparatively shallow in depth having vertical sides rigidly joined -together by means c! spaced bridge members 6 located between the cylinders and at the ends of the member. The lower chords of the bridge members are indicated at 9, and the members have openings indicated at 8. The box-girderlike member 3 has a flat upper face having openings 2 adapted to receive the cylinders I, and to this face the cylinder heads are secured. The" various parts of box-girder-like member 3 are so formed and are of such thickness of material as to provide a structural member of great strength and rigidity.

'I'he remainder of the engine frame is a composite structure made by welding together suitable sheets and structural shapes. Thus, the boxgirder-like member 3 is secured by welding, on the one hand to the vertical transverse plates 4 which are arranged in spaced relation between each pair of adjacent cylinders, and on the other hand to an outer metal casing 5. `As will be seen presently, these elements of the engine frame serve to support the engine upon its foundation and to take the reaction of the forces transmitted between the engine pistons and the crank sha-ft. The casing for the crank shaft is also supported by these elements of the engineframe. The boxgirder-like member 3 thus serves to reinforce the engine frame as a whole.

The cylinders are inserted in the openings 2 of the member 3 and are firmly secured therein. In order to support the lower portions of the cylinders I, there are arranged between the transverse plates 4 and the casing 5 a series of horizontal plate-like members II (Figure 2) each secured by welding its edges to the adjacent plates 4 and to the casing 5 at each end. Secured to the plates Il on each side of each cylinder I isa centering ring I2 which whilst preventing radial movement of the cylinder` permits it to move in the axial direction. 'Ihe outer walls of each cooling water space I3 surrounding each cyll inder I are formed partly by the plates 4 and partly by the surrounding casing 5, each cooling space being separated from the crank case I4 by the plates II. Between each cylinder I and lts associated centering ring I2 are provided pack- 4 ing rings I5 which prevent cooling water escaping from the cooling space I3 into the crank case For the purpose oi securing transverse plates 4 to the box-girder-like vmember 3, the chords 9 of bridge portions 6 of this member are slitted through, as shown at 1 in Fig. 1. Vertical slots in alinement with slits 1, as indicated at 1 in Fig. 3, are also provided, and the bridge portions are also slotted, as indicated at 1" in Fig. l. The slots just mentioned open into apertures 9 in the bridge portion 6. The upper ends of transverse plates 4 are inserted in slits 1 and slots 1 and 1" and the intersections of the edges of these slits and slots with the `apertures 8 are welded to the adjacent faces of the plate lying within these apertures. The lower edges of the chords 9 are alsof welded to the faces of plates 4 as may be seen in Fig. 1. l

The outer casing 5 serves, with the transverse plates 4, to form the supporting and'workingforce resisting portion of the engineframe, and the plates of casing. 5 are provided with spaced projections II) which are welded to ythe vertical sides of the box-girder-like member 3, as shown, for example, in Fig. 1. These lugs are positioned between adjacent pairs-oi cylinders and opposite u the bridge portion 6, and assist in absorbing the stresses caused by the working forces exerted between the cylinders and the bearings.

The cylinder heads (shown in Figs. 6, 7, and 8) are secured to themember 3 by bolts screwed into tapped bores I6 (Figure 3).

With a view to facilitating assembly' of the crank shaft in the crank case, as shown in detail in Fig. 7, the engine is divided at I1 into upper and lower parts connected together by bolts I8 which pass through flanges I9 and 20 formed on the upper and lower parts respectively. The crank shaft bearings 59 are supported by cast steel brackets 2I to which the crank shaft casing 22 is secured by Welding. In order to support the engine upon'its foundation, strips 23 are provided'extending longitudinally along each side, these strips being attached to the casing by means of triangular projections 24 which are welded to the casing. To the lowermost part of the crank shaft casing 22 are welded members 25 thus forminga closed trough made of plate metal and adapted to receive lubricating oil. The casing 5 is furnished with openings 26 for permitting access to the moving parts adjacent to the crank shaft, these doors being closed during operation of the engine.

In the modified form of the invention illustrated in Figures 4 and 5, the crank shaft bearings are suspended on the transverse plates 4, the crank case or sump 28 being separable from the upper part of the frame along the plane 21. Thus, after detaching the sump 28 the crank shaftcan be fitted into the bearings 33 from below. Surrounding each cylinder I is an annular member 29 whereby a narrow passage for cooling liquid is provided so that the speed of the cool.- ing water and therefore the rate of transmission of heat is increased at that part of the cylinder adjacent to the member 29. The lower end-of each transverse plate 4 projects through recesses 30 milled in the casing 5 as shown in Figures 4 and 5 so that the webs 3I thus formed by the lower ends of the plates 4 transmit'the forces through supporting beams 32 to the foundation. In this way forces are transmitted directly from the cylinders through the transverse plates 4 to the foundation.

In the modifications illustrated in Figs. 6 and 7 the valve actuating mechanism of the engine is shown as being supported partly upon the boxgirder-like member 3 and partly upon the cylinder head 3. Thus the supports for bearings 34 of the cam shaft 35 may be .attached to member 3 by welding or by being cast integrally therewith, or by means of bolts, or otherwise. The valves 4I are actuated by a rock arm 40 pivoted on a rock shaft 42 which is carried in brackets 43 attached to the cylinder head 3. It will b understood that cams 36 on shaft 35 coact withtappets 31 which slide in guides 38, the tappets actuating rock arms 40 through rods 39. Guides 39 may be attached to cylinder head 3' as shown in Figs. 6 and 7, or to member 3.

The support of the bearings 34y is reinforced by ribs 44 round'which passes a curved portion 45 of the casing 49 which encloses and protects the valve gear. The casing 5 is furnished at its upper edge with lugs I0 as in the construction above described, each of these lugs having a slot through which one of the\ribs 44 passes, each rib being then welded to the casing 5. It will be seen that thewhole of the valve mechanism is protected from dust and outward injury bythe casing 46.

Between the two valves 4I associated with each cylinder head is arranged a fuel injection device 20' passing through flanges indicated by the numerals' I9 and 20. Further, shoulders 50 are provided adapted to be engaged by the yokes 50a by which the upper bearing saddles are held in position.

If desired the whole valve gear casing and the bearings 34 may be constructed so as to form a y single unitwith the member 3 as shown in Figure 8 in which the curved portion 5I of the casing and the supporting ribs M are formed integral. In this construction the casing 5 is buttwelded to the member 3. A cast construction is shown in Fig. 8 and a welded construction in Fig. 11. Inthe modification illustrated in Figs. 9 and l0, the construction of the engine is substantially identical with the construction as shown in Figs. 1 to 3,except for the fact that the cooling water is prevented from coming in contact with any of the welded joints of the engine frame. This is accomplished by surrounding each cylinder I with a cylindrical jacket 55 mounted in slightly spaced relation toits cylinder, cooling medium .being circulated through the space between the jacket and cylinder. Jacket 55 is welded at its upper end to member 3 and at its lower end to centering ring I2. Inasmuch -as the welded -joints of the engine frame such as joints 56 and 51 are outside of jacket 55, they are protected against corrosion by the cooling medium, and in this way the tendency for premature fatigue at such welded joints is reduced.

In the embodiment of the invention illustrated in Fig. 1l, the box-girder-like member 3a, instead of being of cast construction, is composed of metal plates or sections welded together. As f shown, the sides 58 and 59 of the .box-'girder-like member consists of comparatively narrow, but relatively heavy, at steel plates ci a length corresponding to that of the engine, and the upper member 60 constituting the upper face of the box-like-girder member is a steel plate somewhat thicker than the side plates 58 and 59 and-welded thereto as shown in Fig. l1. This plate 60 is provided with spaced openings 2 for the cylinders I as in the construction shown in Fig. 3.

It will be understood that the invention may be applied to internal combustion engines, steam engines, hydraulic motors, pumps or compressors. In the case of steam engines, however, the cooling chambers surrounding the cylinder liners would be used as insulation against the outward transmission of heat whilst in the case of hydraulic motors and pumps the cooling chambers `may in some cases be omitted. In the ease of .compressors or pumps dealing with hot liquids and provided with openings for receivingl box-girder member, a crank-shaft having bearings and. bearing supports, a plurality of spaced transverse plates connecting said bearing supports and the box girder member, a casing enclosing the lower portion of the crank-shaft and longitudinal side plates extending from the sides of said casing to said box-girder member, said side plates having spaced tongues along their upperJ edges welded tothe sides of said boxgirder member.

v2.'In a welded frame for reciprocating piston apparatus of the character described, a member of weldable material having the form of a box, girder and provided with openings for receiving the cylinders, cylinders mounted within said openings, a cylinder head member secured to said box-girder member, a crank-shaft having bearings and bearing supports, a plurality of spaced transverse plates connecting said bearing supports and the box-girder member, a casing enclosing the lower portion of the crank-shaft and longitudinal side plates extending from the 'sides of said casing to said box-girder member, said side plates having tongues at their upper edges disposed between each pair of adjacent cylinders and welded to saidbox-girder member so as to transmit forces from those parts of the boxgirder member between the cylinders directly to the bearings. A

3. In a welded frame for reciprocating piston apparatus of the character described, amember of weldable materialhaving the form of a boxgirder and provided with openings for receiving the cylinders, cylinders mounted within said openings, a cylinder head member secured to said box-girder member, a, crank-shaft having bearings and bearing supports, a plurality of spaced transverse plates connecting said bearing supports and the box-girder'member, a casing enclosing the lower portion of the crank-shaft, longitudinal side plates extending fromv the sides of said casing to said box-girder member, a supporting member for the apparatus extending longitudinally along each side of said casing, and lateral extensions on the sides of said transverse plates projecting through apertures in the side plates and secured to said apparatus supporting members.

4. In a welded frame for reciprocating piston apparatus of theY character described, a member of weldable material having the form of a boxgirder and provided with openings for receiving the cylinders, cylinders mounted within said openings, a.' cylinder head member secured to said box-girder member, a crank-shaft having bearings and bearing supports, a plurality of spaced transverse plates connecting said bearing supports and the box girder member, said box girder member having a. pair of alined vertical grooves between each two adjacent cylinders, and the upper portion of one of said transverse plates being received ineachpair of said grooves and secured therein by welding.

' 5. .In a welded frame for reciprocating piston apparatus of the character described, a member of weldable material havingthe form of a boxgirder and provided with openings for receiving the cylinders, cylinders mounted within said openings, n cylinder head secured to said box-girder member, said box-girder member being open at the bottom and provided with spaced bridging members extending between the vertical side walls thereof andv disposed between each two adjacent cylinders, each of said bridging members having a slit therein and the walls of said box-girder member having slots in alinement with the slit in each bridge member, a transverse plate positioned in each of said sets of coacting slit and slots and secured therein by welding, and a crankshaft having bearings and bearing supports, said bearing supports being held in position with respect to the cylinders of the apparatus by means Aof said transverse plates.

6. In a reciprocating piston apparatus of the character described, a welded frame structure surrounding and supporting the cylinders thereof including a member extending longitudinally of said apparatus to which the upper ends of the cylinders are secured, a member for laterally supporting the lower ends of said cylinders, and vertical structural members connecting said longitudinal member and said laterally supporting member and secured to the same by welding, and a jacket surrounding each of said cylinders in spaced relation therefrom and disposed inwardly of said vertical frame member to provide a space for the circulation of cooling medium and prevent such medium from coming in contactwith the Welded joints of said frame structure, the upper end of said jacket being attached to said longitudinal member, and the lower end to said laterally supporting member.

'7. In a frame for reciprocating piston apparatus of the character described having cylinders, y

receiving said cylinders, and a composite frame structure for supporting the lower ends of said cylinders and the crankshaft, said composite structure being united to said rigid unitary structural member.

8. In a frame for reciprocating piston apparatus of the character described having cylinders, cylinder heads and a crank shaft, a substantially rigid unitary structural member extending lengthwise of the apparatus adjacent the upper ends of the cylinders and having openings therein for receiving said cylinders, and a composite frame structure united thereto for supporting the lower ends of said cylinders and the crank-shaft, said unitary structural member having a depth which is comparatively small withrespect to the length of the cylinders.

9. In a welded frame for reciprocating piston apparatus o f the character described having cylinders, cylinder head members and a crank shaft having bearings and bearing supports, a structure for supporting said cylinders and cylinder heads, a pluralityvof spaced transverse plates connecting said structure and said bearing supports, a casing enclosing the lower portion of said apparatus, supporting members for the apparatus extending longitudinally of said casing at each side respectively, and lateral extension on the sides of said transverse plates projecting throughapertures in said casing and secured to said apparatus supporting members.

10. In a welded frame for reciprocating piston apparatus of the character described having cylinders, a crank shaft, bearings and bearing supports, a beam of weldable material having the form of a box girder extending lengthwise of the apparatus adjacent the upper ends of said cylinders and provided with openings for receiving the cylinders, said beam having two parallel sides rigidly joined together by spaced bridging members, a structure for supporting the lower portions of said cylinders, including a plurality of spaced transverse plates connecting said bearing supports and the said beam, the upper portion of said transverse plates being secured to the spaced bridging members of said beam.

11. In a frame for reciprocating piston apparatus of the character described havingcylinders, cylinder heads and a crank shaft, a beam in-the form of a box-girder extending lengthwise of theapparatus adjacent the upper ends of the cylinders and having openings therein for receiving said cylinders, and a frame structure for supporting the lower ends of said cylinders and the crank shaft, said structure being united to said box-girder-like beam.

12. In a frame f or reciprocating piston apparatus of the character described having cylinders, cylinder heads and a crank shaft, a beam Y having the form of a box-gilrder extending lengthwise of the apparatus and having openings therein for receiving the cylinders, said beam being narrow compared with the length of the cylinders and disposed adjacent the upper ends therecf, and a frame structure for supporting the lower ends-of said cylinders and the crank shaft, said structure being united to said beam.

CHARLES SCHAER. 

